@James8 welcome to the forums.
One of the best things I have found when I bottle thoughts and feelings up is to let them be realised and get them out of my head and body. One way is to write down all your thoughts and feelings on paper so I am able to realise all that weight and tension from my body and i feel so much lighter and my head does'nt have so much noise going on. It makes this easier to concentrate on in everyday life.
It also gives me a chance to reflect on what I was going through maybe with work or friends, family issues at the time i was caught up in these feelings. Being able to look back can give you an insight into why you may have had those thoughts, what could have been a trigger for them, what signs should I look out for when I start feeling them same way.
I would also consult your gp to see if you have depression and its something they can monitor as it can go up and down, be seasonal like changes in weather or hang around for a long period of time. They may suggest other therapies you could try to help you like meditation, talking in online support groups like SANE etc. They may suggest a trial of anti depressants for a short period of time to help with your thoughts and turn down your anxiety.
I have gone through major depression and anxiety, panic attacks, social phobia and being very isolated and withdrawn. I had to learn that I had concious thoughts and unconcious thoughts and how they effected me personally and my life and how to learn to overcome them or atleast settle them down and for them from ruling my happiness and life.
It takes a lot of time, effort and therapy but it can get better, you certainly arent alone in feeling the way you do and its pretty common.
I still have major depression and anxiety at times but no where as near as bad as I had years ago. I have been able to overcome social phobia and let people in knowing I may get hurt for being vunerable but everyone has some vunerable thing about them. And sometimes you just have to fake that you have all this confidence even when you don't to achieve the things that have held me back from making new friends to finding the right relationship. I have studied and held down a job for many years.
But each took baby steps and help from gps, counsellors, psychologists etc to learn techniques to beat my own negative self talk, hours of practice and building my self worth and confidence.
There is no shame even in the country for saying im not ok, I need some help.😊